// https://leetcode.cn/problems/combination-sum-iv/
// Created by ade on 2022/11/23.
// 给你一个由 不同 整数组成的数组 nums ，和一个目标整数 target 。请你从 nums 中找出并返回总和为 target 的元素组合的个数。
#include<iostream>
#include<vector>
#include<algorithm>

using namespace std;

class Solution {
public:
    // 暴力会超时
    int count = 0, len = 0;
    int combinationSum4(vector<int> &nums, int target) {
        sort(nums.begin(), nums.end());
        len = nums.size();

        for (int i = 0; i < len; i++) {
            dfs(nums, target, nums[i]);
        }
        return count;
    }

    void dfs(vector<int> &nums, int &target, int total) {
        if (total > target) {
            return;
        }
        if (total == target) {
            count++;
            return;
        }
        for (int i = 0; i < len; i++) {
            if (total + nums[i] > target) break;
            dfs(nums, target, total + nums[i]);
        }
    }
};

int main() {
    Solution so;
    vector<int> nums = {1, 2, 3};
    cout << so.combinationSum4(nums, 32) << endl;
    return 0;
}